<template>
  <div>
    <router-link
      tag="div"
      to="/"
      class="header-abs"
      v-show="showAbs">
      <div class="iconfont header-abs-back">&#xe624;</div>
    </router-link>
    <div
      class="header-fixed"
      v-show="!showAbs"
      :style="opacityStyle"
    >
      <router-link to="/">
        <div class="iconfont header-fixed-back">&#xe624;</div>
      </router-link>
      景点详情
    </div>
  </div>
</template>

<script>
export default {
  name:'DetailHeader',
  data(){
    return{
      showAbs:true,
      opacityStyle: {
        opacity:0
      }
    }
  },
  methods:{
    handleScroll(){
      const top=document.documentElement.scrollTop
      if(top>60){
        let opacity= top/140
        opacity=opacity>1?1:opacity
        this.opacityStyle={opacity}
        this.showAbs=false
      }else{
        this.showAbs=true
      }
    }
  },
  activated(){
    window.addEventListener('scroll',this.handleScroll)

  },
  deactivated(){
    window.removeEventListener('scroll',this.handleScroll)
  }

}
</script>

<style lang="stylus" scoped>
  @import '~@/assets/styles/varibles.styl'
  .header-abs
    position: absolute
    left: .2rem
    top: .2rem
    width: .8rem
    height: .8rem
    line-height: .8rem
    border-radius: .4rem
    text-align: center
    background: rgba(0, 0, 0, .8)
    .header-abs-back
      color: #fff
      font-size: .4rem
  .header-fixed
    z-index: 2
    position: fixed
    top: 0
    left: 0
    right: 0
    height: $headerHeight
    line-height: $headerHeight
    text-align: center
    color: #fff
    background: $bgColor
    font-size: .32rem
    .header-fixed-back
      position: absolute
      top: 0
      left: 0
      width: .64rem
      text-align: center
      font-size: .4rem
      color: #fff
</style>
